Fiber optic diffusers are well known in the art. Such diffusers are structured for two quite different classes of procedures within the human body. The first of these procedures is a light diffuser for promoting photochemical reactions within the body.
The generally accepted term for procedures employing light diffusers for use in promoting photochemical reactions is "Photodynamic Therapy" (PDT). Such procedures are the primary procedures for treating cancer in humans or animals. One type of diffuser useful in PDT is the cylindrical diffuser or "line Source".
A fiber optic cylindrical diffuser is characterized by a cylindrical light scattering pattern symmetrical with respect to the central axis of the optical fiber. Such apparatus has been made with an optical fiber having an exposed core portion at one end with a scattering medium coated on the exposed portion.
The apparatus also includes a tube attached to the sleeve covering the clad portion of the fiber adjacent the unclad portion. Copending application Ser. No. 08/007,112, filed Jan. 21, 1993 (now allowed) and assigned to the assignee of the present application describes one such cylindrical diffuser for PDT.
The second class of procedures employing the general structure of a cylindrical diffuser distributes uniform light that generates heat at the distal end of the fiber. Such apparatus is employed, for example, to provide a heat delivering probe for prostate surgery. The present invention is directed at providing an improved diffuser for the generation of a uniform light distribution profile that generates uniform heat in the human or animal tissue.